A network of batteries can be used to provide power source redundancy for critical consumer and commercial applications. The battery network includes several batteries connected together in series, parallel, or other combinations. The applications can be active or passive. In one example, an active battery network powers a consumer's electric automobile. In another example, a passive battery network provides redundancy and failover protection for a commercial server system using electricity wired from a power grid as a primary power source.
Battery performance can degenerate or become unreliable in response to the presence of manufacturing defects or the development of conditions such as grid corrosion, sulfation, or loss of water. Accordingly, maintenance of battery networks is important to ensure reliable performance. But testing a battery for performance characteristics such as cold cranking amps, state of charge, and the like, require that it be removed from use. Alternatively, a battery network can be deactivated and tested as a whole.
Furthermore, state of the art battery testing techniques are unable to identify a specific reason that a battery is failing, or has failed. Consequentially, an operator does not have the opportunity to ameliorate or at least slow down the impending failure. Some types of batteries, such as valve-regulated lead acid (VRLA) batteries, have a higher failure rate and have more catastrophic failures, so the lack of information about the battery condition is especially debilitating.
Therefore, what is needed is a technique for testing battery networks that can be applied while the batteries are in operation to identify and potentially ameliorate a deteriorating condition for a battery.